Estudo sistemático com complexos de inclusão a base de ciclodextrinas no controle de interferentes químico-ambientais : uma metodologia teórica.

• Ano de defesa: 2009
• Autor(a) principal: Xavier, Maria Jose
• Orientador(a): Costa Júnior, Nivan Bezerra da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Sergipe
• Programa de Pós-Graduação: Pós-Graduação em Química
• País: BR
• Palavras-chave em Português: Métodos semiempírico; Ciclodextrinas; Perturbadores endócrinos; Esteróides; Cálculos de RMS
• Palavras-chave em Inglês: Semiempirical methods; Cyclodextrins; Endocrine disruptors; Steroids; Calculation of RMS
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: https://ri.ufs.br/handle/riufs/6122

One of the major environmental problems under discussion is related to the fact that natural and synthetic hormones have been frequently found in effluent from Wastewater Treatment Sewage (TSE) and natural waters, as well as the fact that conventional treatments are not effective in removing these substances. These substances are one recent class of environmental contaminants that interfere with the functioning of the human endocrine system and are related to occurrence of several types of cancer. In the attemp to solve this problem, we propose a study, from a theoretical approach, with cyclodextrins (CDs) molecules, that can be able to form inclusion complexes with many organic substances, poorly soluble in water, thus we believe that CDs are complexing agents promising for this task. In this work we studied the complexation of four steroid drugs commonly found in Wastewaters, with fourteen βCDs chosen, under different criterion to determine one CD more promising for the removal these steroids from the environment. Initially, we propose us to identify a semiempirical method can be better in describe the crystal structure of many compounds on the inclusion of CDs. On a second step applying a study about the formation of inclusion complexes with steroids, investigating two inclusion modes: in and out. The initial calculations indicated the PM3 method as the best method in the structural description of this type of system. Since the results of the complexation with steroids suggest that, in general, the structural orientation energetically more favorable corresponds to out arrangement. An analysis about the interactions more significant to the stability of the complex shows that the LH and the interactions dipole-dipole has a small contribution to the stabilization of the complexes, on the other hand, the hydrophobicity of the substituents on steroids rings, has been pointed as a crucial force to decide how s more stable the steroid enters towards the cavity of the CD. And finally, the results show that in general, all the CDs investigated, theoretically, have similar behavior among themselves.